Pressure operated vapor-liquid selector valve for l. p. g. fuel systems



March 11, 1958 H. SIMONS'ON 2,826,043

PRESSURE OPERATED VAPOR-LIQUID SELECTOR I VALVE FOR L. P. G. FUELSYSTEMS Filed July 28. 1953 2 Sheets-Sheet 1 FIG. 2

FIG.

INVENTOR. H.E.SIMONSON ATTORNEYS 1958 H. E. SIMONSON 2,826,043

PRESSURE OPERATED VAPOR-LIQUID SELECTOR VALVE FOR L. P. c. FUEL SYSTEMSv 2 Sheets-Sheet 2 March 11,

Filed July 28, 1955 I N a x I 7 8 I; 0L I I 5, "I 1' I l! INVENTOR.

H.E.SIMONSON ATTORNEYS Unite 2,826,043 PRESSURE, OPERATED NAPGR-LIQUIDSELEC- Appliwfitm y 19 3, S th! N 7 19 21 Claims. (Cl. 62i-1) Thisinvention relates to internal combustion engine operations. in oneaspeet it relates to an improved apparatus for use with liquefiedpetroleum gas an an internal combustion engine fuel. In another aspectit relates to a 'liquid-vapor selector valve for the selectivewithdrawal of liquid and vapor inresponse to tank pressures formaintaining tank pressures at minimum.

An object ofthis invention ist'o provide an apparatus for controllingthe pressure of liquefied petroleum gas fuel in internal combustionengine fuel tanks when the engine is powered with liquefied petroleumgas.

Another object of this nventionis to provide an apparatus for use inmaintaining relativelylow pressures in liquefied petroleum gasautomotive fueltanks under atmospheric and road temperatures.

Another object of my inventionis to provide an apparatus for use inmaintaining relativelylow pressures in liquefied pe roleum gas fueltanks under high temperature operating conditions which apparatusissimple and inexpensive to make, and safe. and reliable in operation.

Yet another object of my invention isv to provide a vapor-liquidselector valve for usewith LPG tanks which may be subjected tocomparatively, wide variations in ambient temperature, such asencountered in the operation of trucksand buses.-

Still other objects-and advantages of my invention will bev obvious tothose. skilled in theqart upon reading the followingspecification anddrawing, which respectively describes and; illustrates preferred:embodiments of my invention.

T hetern s Liquefied Petroleum Ga-sfi and LPG as used hereinbelow referto.- comrnercial liquefied petroleum gas, suchas commercial, propane.gas includes, in addition to propane, such other hydrocarbons as butane,isobutane, isopentane; and th like. While one or more of these otherhydrocarbons may be present in the commercial propane or liquefiedpetroleum gas they are ordinarily present in relatively small amounts.However, they may be present in appreciable amounts but ordinarilycommercial propane contains largelypropane. The presence of any of theseother-hydrocarbons in propane exerts atleast some efiect on the vaporpressure of propane,- suchelfect however beingsmall when theconcentrations of theseother, hydrocarbons are small. Such.

l ht fi s swi hs es rs ilts 1 qqm ci p op i h-sw ms ma ssut sq thsseother lower vapor pressure hydrocarbons; are neglig-ible and the vaporpressure of commercial propane. orliquefied petroleum gas willhereinafter bereferredto merelyia-sthe vapor pressure o'fpropaneorof-liquefied'petroleum gas.

Since the. vapor pressure of commercial propane is about 200 lbs. persq. in. at 100 F. the use of relatively heavy pressure fuel tanks isnecessary. At temperatures higher than 100 F. which temperaturesaresometimes encountered during certain seasonsoffthe year, propane hasstill higher vapor pressures thanthe. above mentioned 200 lbs. Thus, theutilization of this liquefied fuel under Liquefied petroleum- StatesPatent suchtemperature and pressure conditions becomes a problemrequiring-careful consideration.

According to myinvention I have provided a pressure operatedliquid-vapor seleetor valve in which a pressure operated motor actuatesa piston for selecting vapor or liquid for withdrawal from the tank.When the pressure in the tank is relatively lowthe motor operates thepiston to close off a port leading to the vapor containing portion ofthe tank and opening a--portleading to the liquid containing portion ofthetank for removal of liquid, 0pm: plemen'tarytothis when pressureinthe tank is highthe motor operates the piston-to close ofi the portleading to the liquid containing space and opening the port leadingtothe vapor containing-space of the tank thereby permit ting Withdrawal ofvapor, Which-operationis followed by evaporative cooling andultimatereductio-n of pressure. My apparatus can be inserted into an-LPGtank through a single opening, and for the. most part themajor portionoi the liquid-vapor selector valve is disposed Within the tanks-therebyminimizing danger fromdamage to the valve.

In the drawing: Figure 1 is a longitudinaliviewpartlyin sectionof oneembodiment of myinvention.

Figure 2, is a longitudinal. View, partly in section-of;

another embodiment of my invention.

Figure; 3- is a sectional viewof anendplate useful Withthe apparatusembodimentofe Figure 2 Figure 4 is alongitudinal view, partly insection,of still another embodimentofi my invention.

Figure 5 is a diagrammaticview of the. liquid-vapor selector valveassembly of; my invention in conjunction with an autornotive fuejlsystem.

Figure 6 a longitudinal sectionalviewv of a portion of. the apparatus ofFiguresd, 2, 4; and 8.

Figure 7 "is a longitudinal-view, partly insection, of'a iw ith pp ratusof F gu 5 u a on ud na apparatus for use in conjunction with aportiomofr the apparatus. of Eigure 4.

Referring-now to the-drawing and-specifically to Figure 1, thisvapor-liquid selector:valve eonsists-of a cylindrical" housing member llcontaining a movable-piston 1 3; To-

this, piston, is attacheda piston rod 17 which in turn-isconnected, to apressure/ 1 operative, motor-- 15. ThiS- P IIS'1. sure operative; motorin the embodiment of Figure 1 is: illustrated; asratpressure opfilativebellows. This-bellows; is provided with a compression spring19. forassisting. This llows s. s, e tioned ab at p ssure sspqnsiv f ellows andit is.pr er hly=at eastp r i l y evasuat da o thebellows, to expanduponreduction ot'pressu ei minimize the effect of temperature changes. Thishel-g lowsis supported by a base 151316221: whichforms the end wall of,tho-cylindrical. housing 11. A port 27 is; pro-.

vided inthe upper s de Wa-lLhousing 11 for; admittance;

or fuel vapor While another port 23 is provided as shown, To. thisport 23; is attached a diptl be 29 which isintended;

to dip into liquid fuel in tank 37. A- conduit 25 is dis p s d hr ghout.he ength of p n. 13 o p s asewq qu from p ce be ow he p ton-tome pa e.ab e. the piston. The upper endpof the housingme nber 11;.

is provided with a flange 12 for installation purposes.

Bolts 33 hold fian ge 12 rigidly againsta ring 3 5 wh ich in turn iswelded or attached otherwise to the walls of,

the tank 37;. Element 31 is an excess flow valveof moreor lessconventional type.

In the operation of the apparatus embodiment illustrated in Figure 1whenpressure within the tank increases,

to a value higherthan a preselected pressure the bellows 15 tends to.contract thereby lowering piston 13 to close port 23 and open port 27.Vaporous LPG fuel enters the: housing 11' bypwayiof port 27 andpasses-through the excess;tlowvalvafikfor useiins the engine. Whenpres-1 view, partly in section, of-

asaaoes sure within the tank 37 decreases to a value below saidpredetermined pressure the bellows expands with the assistance of thecompression spring 19 thereby raising piston 13 to close port 27 andopen port 23. Under this condition the source of the vaporous fuel isclosed off and liquid fuel may be admitted through dip tube 29 and port23 into the housing 11 below the piston 13. This liquid then flowsupward through conduit and through the excess flow valve 31 to the fuelconduit.

In Figure 2 of the drawing reference numeral 47 identifies a selectorvalve housing provided with a piston 49. A tubular piston rod 51 isfitted into piston 49 so as to provide a passageway from the space atthe bottom of thehousing 47 to the space above the piston. An end plate61 closes the lower end of the housing 47. Centrally disposed on the topsurface of this end plate is a resilient sealing member 63, such as ahydrocarbon-proof synthetic elastomer. The bottom end of the tube 51 isintended, to act as a valve for seating against the sealing member 63when the piston is at the lower end of its extent of travel. Tube 65 isprovided. for dipping into liquid fuel in the tank and through whichliquid fuel is drawn into the selector valve. A pressure operative motoris illustrated in Figure 2 as a pressure operative bellows. This bellowsis also provided with a compression spring 55 for assisting expansionunder reduced pressure conditions. A circular plate 57 is attached tothe upper end of the bellows and to the tube 51 in such a manner that asthe bellows expands or contracts piston 49 moves respectively upward ordownward. An annular plate 59 serves as a base for the bellows 53 andthis base is attached rigidly to the housing member 47 as'illustratecl.A port 67 is provided in the upper side wall of housing 47 for inlet ofvapor. A flange is provided for use of bolts 43 for attaching thisassembly to ring 41. This ring may be attached rigidly to the tank wall39 by any method desired, such as by welding. An excess flow valve isprovided for controlling the outlet of fuel from this selector valve, i.e., the excess flow valve closes ofl entirely the flow of fuel in caseof breakage of the fuel line.

By the use of the liquid dip tube 29 of Figure 1 and dip tube of Figure2 the respective valve housings may be relatively short since the diptubes are intended to be sutficiently long to extend substantially tothe bottom of the fuel tanks. Under some conditions it might bedesirable not to use a liquid dip tube. The end plate 69 of Figure 3 canbe inserted into the lower end of housing 47 of Figure 2 in place of endplate 61. This end plate 69 is provided with one or more openings 71 foradmission of liquid into the housing. A resilient hydrocarbon-proof seal73 is provided for sealing the bottom end of tube 51 against inlet ofliquid when piston 49 is at the lower end of its extent of travel. Whenusing the end plate 69 of Figure 3 in place of end plate (61'and diptube 65) the cylindrical housing member of the selector valve must besufliciently long that the end plate 69 is positioned at a level verynear the bottom of the tank. The openings 71 merely replace the dip tube65 of Figure 2 for inlet of liquid. Otherwise the construction andoperation of the selector apparatus With end plate 69 is similar to aconstruction and operation of the embodiment of Figure 2.

In Figure 4of the drawing this embodiment of selector valve includes ahousing member 91 intended to be installed within the tank 99. A housingmember 75 is disposed outside of the tank and a flange-102 integral withhousing 75 is held by bolts 103 to ring 101 which in turn is fastened,for example, by welding to tank Wall 99. To the outer end of theexterior housing 75 is provided a diaphragm 79. This diaphragm is heldin place by a bonnet 77 and bolts 107. An excess flow valve is providedin the bonnet 77 for closing off this apparatus to the escape of fuel incase of rupture of diaphragm 79.

This excess flow valve is also intended to serve as a pressureequalizing vent to maintain the space under the bonnet and above thediaphragm at atmospheric pressure. However, in case of rupture ofdiaphragm 79 and admission of high pressure gas to the space under thebonnet this excess flo'w valve prevents escape of combustible fuel. Acompression spring 83, adjustable by a spring adjuster 81, is providedfor assisting movement of piston rod 87 and piston 89. A shoulder 92 isprovided in the upper part of the housing 91 to prevent expulsion ofpiston 89 in case of accidental breakage of the exterior housing member75. An excess flow valve 105 is also provided for controlling outlet ofLPG from this selector valve to the engine.

An end plate 93 is provided in the bottom end of interior housing 91.Piston 89 is provided with a conduit 109 for passage of liquid from thespace below the piston to the space above the piston. An excess flowvalve 108 is disposed in conduit 109 for closing olf fluid flow in caseof accidental rupture of the exterior housing 75. In case of accidentalbreakage of housing 75 piston 89 will be immediately forced upwardagainst shoulder 92 and excess flow valve 108 will then operate to closeoff all flow of fluid from the tank to the rupture area. A port 95 isprovided in the inside housing member 91 as shown. A liquid dip tube 97is provided for passage of liquid from the liquid containing space ofthe tank into the selector valve as shown.

, In the operation of the selector valve of Figure 4 when the pressurewithin the tank .has been decreased to a value below a predeterminedpressure the diaphragm 79 with the aid of spring 83 forces the piston 89downward to close the vapor inlet port 95 and open port 96 for inlet ofliquid fuel. Under these conditions liquid will be admitted through diptube 97 into the space above the piston 89 and this liquid will thenflow upward into the housing 75 and outward through the excess flowvalve to the fuel conduit.

When the pressure in tank 99 increases to some predetermined pressurethe diaphragm 79 will be forced upward to move piston 89 upward to closethe liquid admission port 96 and to open the vapor inlet port 95. Underthis condition vapor is admitted through port 95 to the space below thepiston. This vapor will then flow upward through conduit 109 and excessflow valve 108, that is, through the piston, and out through excess flowvalve 105 to the engine. Removal of vapor in this manner continues untilthe liquid contents of the tank have been sutficiently cooled byevaporation that the pressure decreases to operate the diaphragm andpiston assembly to close ofl the vapor and open the valve for removal ofliquid.

in the embodiments of my invention the several pistons may under someconditionsv remain in an intermediate position allowing removal of bothvapor and liquid simultaneously from the tanks.

In the embodiment of my invention illustrated in F1 gure 4 the pressureresponsive motor is illustrated as a spr ng loaded diaphragm. A springloaded bellows, respons ve to pressure, may be used in place of thespring loaded diaphragm. In Figure 8 of the drawing is illustrated abonnet member 162a provided with a pressure operative bellows 163a. Tothe lower end of this bellows is attached a piston rod 165:: which isequivalent to piston rod 87 of Figure 4. An excess flow valve 167 isprovided in bonnet member 16211 for control of fuel to the engine. Inthis case when pressure under bonnet 162a decreases to below apredetermined value bellows 163a, which is spring loaded, expands tolower the piston, not shown, and admit liquid for passage through valve167 to the engine. When pressure under bonnet 1621: increases to above apredetermined value bellows 163a contracts raising a piston, not shown,thereby closing 01f liquid and opening the valve to the inlet of vapor.

valve 85 does not pass fuel to. .the engine. Excess flow 10a valve 108ofFigure 4 can be similartothe valve illus trated in Figure 6 but thereneed not bea hexagonshaped section. 147 (Figure 6) .since valve .108.isthreadedto the conduit 109. The valveof Figure 6 isprovided withiahexagon shaped section 147 for. useof-awrench. This valve is providedwithra compression-spring. 151 and. a valve member 149, which membersare held .in place by afitting 153 threaded at 159. ThreadslSS .are forin:- stallation of the. valve, while threads. 156 are for fasten. ingaflow line for carrying fuel: from thevalve:

Figure 7 of the drawingillustrates in diagrammatic. torn-ran atmosphericshut-off valve which is intende-dto operate .in such. a manner thatwhenthe engine is: not. running the -valve' automatically .closes .thefuel .carry ing.

line againstcontinued passage ofinfl'ammable-fuelr. This.v 25.;

valve assemblyidentified by reference numeral 140-contains a diaphragm163. Space under the diaphragm. is vented through a vent 165.Diaphragm163. is connected toa valve 161- inline 138* This line 138isthefuel-inlett line to the valve :while conduit 141is the fuel-outletlinc. 0

The fuel outlet .lineldl ismof course connectedatothe carburetor andwhen pressure within. line- 141 i decreases,:'. as byturning over of themotor-instarting, pressure above diaphragm 163 decreases and" thediaphragmopens valve.

161. to permitpassage of fuelto thecarbureton Ob viously during timeswhen .the engine isrunningpressure in-line 141 is below atmospheric andthediaphragm holds. valve161-open. When the engine is stopped pressurein line 141- becomes atmospheric and the. diaphragm 163 aidedbyspringp162 closes valve '161.

In Figure .5 ofwthe-drawing is illustrated; diagrammatically, a completesupply apparatus for-an internal com-. bastion engine using liquefiedpetroleum gas as fuel. A- pressure storage tank ill'contains the fuel,reference-nu meral- 115- identifying the liquid in the tank' and ref-4.5 erence numeral 117 the vapor space above the liquid. Element 119 isa valvedconduit for filling of the-tank. A relief valve 121 isprovidedin case pressurerelief is required. Reference numeral 113.identifies a selector-.-valves.. assembly of my invention 123 isintendedto be connected to the assembly 113.bymeans of such an excessflow valve asvalve 31.or-valve 45. Line or'conduit 123 discharges into.a-.filter element l25-for removal of foreign matterfrom the-,fuel. Fuelfree from foreign matter leaves the filter and. flows .55

through conduit 127 to a pressure regulator 129. This pressure regulatoris intended to reduce pressure. from tank pres-sureto such a pressurethat one additional stage: of pressure:reduction is' sufficient.Apparatus131ris a. fuel vaporizer for making certain that onlyvaporous-fuel reaches: the carburetor. Conduit 133" conducts. waterfromthe automotive cooling systemtto the vaporizenwhile: conduit-135conducts usedv water back tothez cooling sys.-- tern. Vaporous fuelleaves the vaporizer through 'acon- Y duit 137- and passes through a.final, pressure regulator... 139 which is intended to reduce thepressure to.substant-. tially atmospheric. From this latter regulator.fuel .flowsthroughconduit 138 to a valve assemblyJ'40from-Which the fuelpasseson through conduit14-1 to a-carburetor143- and iutakemanifold 145.This assemblyof fuel dispense ing. andhandling apparatus-is such. aswill be :used on automotive equiprnent such as trucks or buseseor even.auto.- mobiles-in caserthese latter vehicles would beppweredby liquefiedpetroleum. gas. Also sucht fucltdispensing and pressurecontrol equipmentis suitable for useawith permas 75' disposed-inthe .tank. Conduit 50*nent. internal. combustion engines such.as.:those used. in: powerplants, compressor. plants andthelikc,

While theselectorvalves describ.ed.hereinaft,er. have; been of the. toptank outlcttype, it is within the scope. of my. invention to adapt thehereindisclosed selector ,valve apparatus-to bottom outlet type fueltanks. In this .case, thefuel outlet. enters the bottom of thetank.Liquid, would enter the port next. the tank-outlet while the, dip. tubewouldbe a gas dip tube-and would extendv upward into the vapor space ofthe .tank.

Materials of construction may beselectedfromamong those commerciallyavailable and adapted for. use in such. applications. It is preferableto use materials not easily corroded-by oxygen and/or moisture.

While certainembodimentsof myinventiorl have been,

described for illustrative purposes, the inventionobvious'lyg is notlimited thereto.

I claim:

1. Aliquid-vapor selector valve assembly for use in, liquefied petroleumgas fuel systems comprising, in com bination, a valve body member, aportion of said valve body member being adapted to be disposed within atank, said valve body member defininga first. conduit, a pres: sureoperative motor in said first conduit, said pressure, operative motorbeing responsive to externally applied pressure, a movable piston drivenby said motor-in s'aid conduit dividing said first conduit into twochambers, a. second conduit in said piston providing fluid communca:tion between said chambers, a port .inthe wall, of said body member forinlet of vapprous fuel, a port in ,the Wall of said body member forinlet of liquid fuel,.said portsbcing dis'pose'd'in the portion of saidvalve bodymember. adapted to be disposed in a tank, saidinovablepistonbeing. disposed in. general intermediate said ,ports' .andin, sucha. manner that upon movement to one .end of its stroke one port becomesclosed andthe otherport opened...

and at the other end ofits stroke said oneport becomes opened and'said,other port becomes closed and an outlet means at least near the outletend of the valve. assembly.

2. In the liquid-vapor selector valve assembly offclairn,

1 wherein said outlet means comprises an excess, fiow valve assembly.

3. In the liquid-vapor selector valve assembly of claim.

1 wherein said motor is a pressure operative bellows.

4. A liquid-vapor selector valve assembly foruse in. liquefied petroleumgas fuel systems comprising, in com bination, a housing member,aportio'n ofsaid housing; member being adapted tobe disposed ,withinatank, a

pressure operative motor in said'housing member, said...

pressure operative motor beingresponsive to,externally applied pressure,a movable piston driven, by saidmotor in said housingmember dividing thespace within said, housing member into an upper chamber and alOWcr,chamber, a conduit throughout the length of said piston providingcommunication. between said, chambers, a; first port in the wall of saidhousing member for inlet, of vaporous fuel, a second port in the wall ofjsaidhous ing member for inlet ofjliquid fuel, said portabeingdis:

posed at different levelsand being in .theportionof said, housing memberadapted 1 to.be dis'p ose'd jin saidstank, said "piston beingdisposed ingeneral intermediate saidl ports and in such. a manner thatupon-movementtothe, upper end of its stroke the upper portisclosedjandthe lower port is opened, and'at the lower end'ofits stroke. theupperport is opened and the lower port isclosed, andlan outlet meansin saidhousing m ember atrleast. near the upper end thereoffor outlet ,of fuel,

5. In the liquid-vapor; selector valve.v assembly of .clairn 4. whereinsaid outlet means. comprises an, excess flow valve. assembly.

6. Inthe liquid-vapor selector valve assembly of clairn- 4 wherein.said: motor. is a pressure-operative.bellows;

7,. A liquidsvapor selector; valve. assembly forg use: in.

liquefied petroleumgasfuel systems comprising, in combination, ,agenerally cylindrical, housing member, said housing memberbeing adaptedfor installation in the top of aliquefied petroleum gas storage tank andso disposed that the axis of said housing is at least approximatelyvertical, an end plate in the bottom end of said housing member, anopening in said end plate, a liquid dip-tube disposed in said opening insaid plate and providing communication from the liquid containing spacein said tank to a space above said end plate, a resilient sealing memberattached to the top center surface of said end plate, a piston in saidhousing member adapted for reciprocating movement therein, a pressureoperative bellows attached to the lower portion of said housing, saidpressure operative bellows being responsive to externally appliedpressure, a tubular piston rod connecting said bellows and said piston,a conduit throughout the vertical length of said. piston, said tubularpiston rod being connected with the walls of said conduit in said pistonand extending downward through said bellows to a level adjacent saidresilient sealing member, the lower end of said tubular piston rod beingadapted to seat against said resilient sealing member at the lower endof the stroke of said piston, a port in the wall of said housing memberat a point above said piston when at the bottom end of its stroke, anexcess flow valve in the upper end of said housing member, and means forattaching the outer end of said excess flow valve to a conduit forpassage of fuel to a point of use.

8. A liquid-vapor selector valve assembly for use in liquefied petroleumgas fuel systems comprising, in combination, a hollow housing member,said housing memher being adapted for installation in the upper wall ofa liquefied petroleum gas fuel tank and so disposed that the axis ofsaid housing is at least approximately vertical, a non-perforate endplate in the bottom of said housing member, a pressure operative bellowsdisposed on the top surface of said end plate and within said housingmember, said pressure operative bellows being responsive to externallyapplied pressure, a movable piston in said housing member, a piston rodconnecting said piston and said pressure operative bellows, a first portin the sidewall of said housing member at a level just above the topsurface of said piston when said piston is at the lower end of itsextent of movement, a second port in the sidewall of said housing memberat a level just below the bottom surface of said piston when said pistonis at the upper end of its extent of movement, a liquid dip tubeextending from said second port to a level near the bottom of said tank,an excess flow valve in the upper end of said housing member, saidexcess flow valve being adapted to control flow of fuel from said tank,and means for attaching said excess flow valve to a conduit for passageof fuel to its point of use.

9Q A liquid-vapor selector valve assembly for use in a liquefiedpetroleum gas fuel system comprising, in combination, a housing member,said housing member being adapted to be attached to the upper wall of aliquefied petroleum gas fuel tank and so disposed that the axis of saidcylindrical housing member is at least approximately vertical, aperforate end plate in the lower end of said housing member, saidhousing member being adapted to extend substantially to the bottom ofsaid tank, a resilient sealing member attached to the top surface ofsaid end plate, a piston in said housing member adapted forreciprocating movement therein, a pressure operative bellows attached tothe lower portion of said housing, said pressure operative bellows beingresponsive to externally applied pressure, a tubular piston rodconnecting said bellows and said piston, a conduit throughout thevertical length of said piston, said tubular piston rod being connectedwith said piston and extending downwardly through said bellows to alevel adjacent said resilient sealing member in such a manner as toprovide a passage from a level below' said bellows to a level above saidpiston, the lower end of said tubular piston rod being adapted to seatagainst said resilient sealing mom-- her when said piston is at thelower end of its extent of movement, a port in the cylindrical wall ofsaid housing member at a level just above the top of said piston whensaid piston is at the lower end of its extent of movement, an excessflow valve in the top of said cylindrical housing member, said excessflow valve being adapted to control flow of fuel from said tank, andmeans for attaching said excess flow valve to a conduit for passage offuel to its point of use.

10. A liquid-vapor selector valve assembly for use in a liquefiedpetroleum gas fuel system comprising, in combination, a housing member,said housing member being adapted to be attached to the upper portion ofa liquefied petroleum gas fuel tank with at least a portion extendinginto the tank, said housing member being so disposed that its axis isapproximately vertical, a movable piston inthe portion of said housingmember adapted to extend into said tank, the bottom end of said housingmember being closed, a pressure operative motor in the portion of saidhousing member adapted to be outside of said tankpsaid pressureoperative motor being responsive to externally applied pressure, apiston rod connecting said motor "to said piston, an excess flow valvein the wall of said' 'housing member adapted to be outside of said tankand below said motor, means for attaching the end of said excess fiowvalve outside of said housing member to a conduit for passage of saidfuel to its point of use, said excess flow valve being adapted tocontrol the flow of fluid from said housing member to said conduit, avapor inlet port in the sidewall of the portion of the housing memberadapted to be inside said tank and at a level just below the bottomsurface of said piston when said piston is at the upper end of itsextent of travel, a liquid inlet port in the sidewall of the portion ofsaid housing member adapted to be inside said tank and at a level justabove the top surface of said piston when at the lower end of its extentof travel, a liquid dip tube extending from said liquid inlet port intothe liquid containing portion of said tank, and a conduit through saidpiston connecting the space above the piston with the space be low thepiston.

11. In the liquid-vapor selector valve assembly of claim 10 wherein saidpressure operative motor is a pressure operative diaphragm disposedgas-tight against the upper end of said housing member outside saidtank, a bonnet disposed gas-tight on the side of said diaphragm oppositesaid housing member and an excess flow valve in said bonnet to regulategas pressure in the space bounded by said diaphragm and said bonnet.

12. In the liquid-vapor selector valve assembly of claim 10 wherein saidpressure operative motor is a pressure operative bellows.

13. A liquid-vapor selector valve assembly for use in liquefiedpetroleum gas fuel systems comprising, in combination, a valve bodymember of generally circular crosssection, means for attaching saidvalve body member vapor-tight to the wall of a tank, a portion of saidvalve body member being adapted to be disposed within said tank whensaid means is attached vapor-tight to said tank, said valve body memberdefining a first conduit, a pressure operative motor in said firstconduit, said pressure operative motor being responsive to externallyapplied pressure, a movable piston driven by said pressure operatedmotor in said first conduit dividing said first conduit into twochambers, a second conduit in said piston providing fluid communicationbetween said chambers, 21 port for inlet of vaporous fuel and a port forinlet of liquid fuel in the wall of said portion of said valve bodymember adapted to be disposed within said tank, said movable pistonbeing disposed in general intermediate said ports and in such a mannerthat upon movement to one end of its stroke, one port becomes closed andthe other open and at the other end tof its stroke, said one portbecomesopened andsaid other portbecomesblosed, and an outlet means atleast near the outlet end of said valve assembly.

- 14. A liquid-vapor selector valve assembly for use .in liquefiedpetroleum gas fuel systems comprising, in com bination, a generallycylindrical housing member, said housing :member being adapted-forinstallation :in the upper portion of a liquefied .petroleum gas storagetank, an end plate in the bottom end of said housing member, an openingin said end plate, a liquid dip-tube disposed in said opening in saidplate and providing communication from the liquid containing space insaid tank to "a space above said end plate, a resilient sealing memberattached to the top surface of said end plate, a piston in said housingmember adapted for reciprocating movement therein, a pressure operativebellows attached to the lower portion of said housing, said pressureoperative bellows being responsive to externally applied pressure, atubular piston rod connecting said bellows and said piston, a conduitthroughout the length of said piston, said tubular piston rod beingconnected with the wall-s of said conduit in said piston and extendingthrough said bellows to a level adjacent said resilient sealing member,a lower end of said tubular piston rod being adapted to seat againstsaid resilient sealing member at the lower end of the stroke of saidpiston, a port in the wall of said housing member at a point above saidpiston when at the bottom end of its stroke, and means for attaching theouter end of said assembly to 'a conduit for passage of fuel to a pointof use.

15. A liquid-vapor selector valve assembly for use in liquefiedpetroleum gas fuel systems comprising, in com bination, a housingmember, said housing member being adapted for installation in the upperportion of a liquelied petroleum gas fuel tank, a pressure operativebellows supported by the inner end and within said housing member, saidpressure operative bellows being responsive to externally appliedpressure, a movable piston in said housing member, a piston rodconnecting said piston and said pressure operative bellows, a first portin the side wall of said housing member at a level above the top surfaceof said piston when said piston is at the lower end of its extent ofmovement, a second port in the side wall of said housing member at alevel below the bottom surface of said piston when said piston is at theupper end of its extent of movement, a liquid dip-tube extending fromsaid second port to a level near the bottom of said tank, and means forattaching the upper end of said assembly to a conduit for passage offuel to its point of use.

16. A liquid-vapor selector valve assembly for use in a liquefiedpetroleum gas fuel system comprising, in combination, a housing member,said housing member being adapted to be attached to the upper portion ofa liquefied petroleum gas fuel tank, a perforate plate in the lowerportion of said housing member, said housing member being adapted toextend substantially to the bottom of said tank, a resilient sealingmember supported by the top of said end plate, a piston in said housingmember adapted for reciprocating movement therein, a pressure operativebellows attached to the lower portion of said housing, said pressureoperative bellows being responsive to externally applied pressure, atubular piston rod connecting said bellows and said piston, a conduitthroughout the vertical length of said piston, said tubular piston rodbeing connected with said piston, and extending through said bellows toa level adjacent said resilient sealing member in such a manner as toprovide a passage from a level below said bellows to a level above saidpiston, the lower end of said tubular piston rod being adapted to seatagainst said resilient sealing member when said piston is at the lowerend of its extent of movement, a port in the cylindrical wall of saidhousing member at a level above the top of said piston when said pistonis at the lower end of its extent of movement, and means 10 forattaching ?the "upper portion-:of :said assembly to :a conduit forpassage offuel to-its point of use.

17. A liquid-vapor selector valve assembly for use in liquefiedpetroleum gas fuel systems comprising, incombination, a housing memberadapted to be attached to the upper portion of a liquefiedpetroleumgasfuel .tank with at least a portion extending into said-tank, a-movablepiston in the portion-of said housing member adapted to extendinto saidtank, a pressure operativemotor in the portion of said housing memberadapted to be outside of said tank, said pressure operative motor beingresponsive to externally applied pressure, a piston rod connecting saidmotor to said piston, means for attaching the portion of said housingmember outside said tank and below said motor to a conduit for passageof said fuel to its point of use, a'vaporinle't port-inthe sidewall ofthe portion of the housing member adapted to be inside said tank and ata level below the bottom surface of said piston when said piston is atthe upper end of its extent of travel, a liquid inlet port in the sidewall of the portion of said housing member adapted to be inside saidtank and at a level above the top surface of said piston when at thelower end of its extent of travel, a liquid dip-tube extending from saidliquid inlet port into the liquid containing portion of said tank, and aconduit through said piston providing communication between the spaceabove the piston with the space below the piston.

18. In the liquid-vapor selector valve assembly of claim 17 wherein saidpressure operative motor is a pressure operative diaphragm disposedgas-tight against the upper end of said housing member outside saidtank, a bonnet disposed on the side of said diaphragm opposite saidhousing member and an excess flow valve in said bonnet to regulate gaspressure in the space bounded by said diaphragm and said bonnet.

19. In the liquid-vapor selector valve assembly of claim 17 wherein saidpressure operative motor is a pressure operative bellows.

20. A liquid-vapor selector valve assembly for use in liquefiedpetroleum gas fuel systems comprising, in combination, a housing member,said housing member being adapted for installation in the upper portionof a liquefied petroleum gas storage tank, a plate in the lower portionof said housing member, an opening in said plate, a liquid dip-tubedisposed in said opening and providing communication from the liquidcontaining space in said tank to a space above said plate, a resilientsealing member supported by the top surface of said plate, a piston insaid housing member adapted for reciprocating movement therein, apressure operative bellows attached to the lower portion of saidhousing, said pressure operative bellows being responsive to externallyapplied pressure, a tubular piston rod connecting said bellows and saidpiston, a conduit through the vertical length of said piston, saidtubular piston rod extending downward through said bellows to a leveladjacent said resilient sealing member, the lower end of said tubularpiston rod being adapted to seat against said resilient sealing memberat the lower end of the stroke of said piston, said tubular piston rodand said conduit extending through said piston providing communicationfrom a space below said pressure operative bellows to a space above saidpiston, a port in the wall of said housing member at a point above saidpiston when at the bottom end of its stroke, an excess fiow valve in theupper end of said housing member, and means for attaching the outer endof said excess flow valve to a conduit for passage of fuel to a point ofuse.

21. A liquid-vapor selector valve assembly for use in liquefiedpetroleum gas fuel systems comprising, in combination, a housing member,said housing member being adapted for installation in the upper portionof a liquefied petroleum gas storage tank, a plate disposed vapor-tightin the lower portion of said housing member, an opening in said plate, aliquid dip-tube disposed in said opening 11 in said plate and providingcommunication from the liquid containing space in said tank to a spaceabove said plate, a resilient sealing member attached to the top surfaceof said plate, a piston in said housing member adapted 'forreciprocating movement therein, a pressure operative bellows attached tothe lower portion of said housing, said pressure operative bellows beingresponsive to externally applied pressure, a tubular piston rodconnecting said bellows and said piston, a conduit through out thelength of said piston, said tubular piston rod being connected with saidpiston in such a manner that the conduit of the tubular piston rodcommunicates with said conduit in said piston, said tubular piston rodextending through said bellows to a level adjacent said resilientsealing member, the lower end of said tubular piston rod 12 beingadapted to seat against said resilient sealing memher at the lower endof the stroke of said piston, a port in the wall of said housing memberat a point above said piston when at the bottom end of its stroke, andmeans for attaching the outer end of said assembly to a conduit forpassage of fuel to a point of use.

References Cited in the file of this patent UNlTED STATES PATENTS 1,50,893 Morrow Apr. 3, 1923 1,940,090 Hetherington Dec. 19, 19331,962,214 Russell et a1. June 12, 1934 2,226,810 Ensign et al. Dec. 31,1940 2,365,423 MacSparron Dec. 19, 1944 2,543,920 MeCabe, Jr. Mar. 6,1951

